Define schema / grammar and parse and instance of it

Question

I'm wondering that is there a Java lib out there which I can use to define a schema and then if I have an instance of that schema, parse it?

I mean like the schema would be looking something like this:

string: [a-zA-Z]+
number: [1-9][0-9]*

attribute: "attribute " name: string " " type: string :: MyParser.newAttribute(name, type)

node: "node " name: string " {" :: MyParser.newNode($name)
    attribute+
"}" :: MyParser.closeNode()

node+

And then an instance of the schema would be looking like this:

node MyNode {
    attribute myAttribute1 Int
    attribute myAttribute2 Long
}

node SecondNode {
    attribute x String
}

And the parser would be generated or I don't know, but it would work like this:

• Whenever it reaches a node line it the MyParser.newNode method would be called
• Whenever it reaches an attribute line, the MyParser.newAttribute would be called
• And whenever it reaches a } line the MyParser.closeNode would be called

Of course I must garantue that the MyParse class with those static methods will exist in my parser project.

Answer 1

antlr -- http://www.antlr.org/ -- was what I wanted.